GLONASS Signal Plan - Revision history

Gema.Cueto at 10:30, 16 April 2026

2026-04-16T10:30:49Z

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	== GLONASS L1 Band ==		== GLONASS L1 Band ==

	The transmitted navigation signal is in both services of L1 a bipolar phase-shift key (BPSK) waveform with clock rates of 0.511 and 5.11 MHz for the standard and accuracy signals respectively. The L1 signal is modulated by the Modulo-2 addition of the pseudo random (PR) ranging code, the digital data of the navigation message and an auxiliary meander sequence. All above-mentioned frequencies are generated coherently using a single onboard time/frequency oscillator standard [GLONASS ICD, ~~2002~~] <ref name="~~GLONASS_ICD_2002~~">[GLONASS ICD, ~~2002~~] ~~GLONASS SIS ICD 2002. Version 5~~</ref>. For the case of the standard accuracy signals (C/A), the PR ranging code is a sequence with length the maximum of a shift register (m-sequence) and a period of 1 millisecond with bit rate of 511 kbps. The navigation message is sent at 50 bps and the auxiliary meander sequence at 100 Hz.		The transmitted navigation signal is in both services of L1 a bipolar phase-shift key (BPSK) waveform with clock rates of 0.511 and 5.11 MHz for the standard and accuracy signals respectively. The L1 signal is modulated by the Modulo-2 addition of the pseudo random (PR) ranging code, the digital data of the navigation message and an auxiliary meander sequence. All above-mentioned frequencies are generated coherently using a single onboard time/frequency oscillator standard [GLONASS ICD, 2020] <ref name="GLONASS_ICD_2020">[https://glonass-iac.ru/upload/docs/stehos/stehos_en.pdf GLONASS ICD, 2020]</ref>. For the case of the standard accuracy signals (C/A), the PR ranging code is a sequence with length the maximum of a shift register (m-sequence) and a period of 1 millisecond with bit rate of 511 kbps. The navigation message is sent at 50 bps and the auxiliary meander sequence at 100 Hz.

	Moreover, it is important to note that the GLONASS FDMA L1 band does not exactly coincide with the GPS and Galileo L1 band. In fact, the GLONASS L1 band ranges from 1592.9525 MHz to 1610.485 MHz when only the 14 channels k = -7...+6 are employed. In the next figures, each of the channels was filtered to only transmit the main lobe of the BPSK signal and the PSD was normalized to have unit power within the corresponding transmission bandwidth.		Moreover, it is important to note that the GLONASS FDMA L1 band does not exactly coincide with the GPS and Galileo L1 band. In fact, the GLONASS L1 band ranges from 1592.9525 MHz to 1610.485 MHz when only the 14 channels k = -7...+6 are employed. In the next figures, each of the channels was filtered to only transmit the main lobe of the BPSK signal and the PSD was normalized to have unit power within the corresponding transmission bandwidth.
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	It is important to note that the GPS L1C pilot and data signals are shown in quadrature in the figure although according to [GPS ICD-800, ~~2006~~]<ref>[~~GPS ICD~~-~~800, 2006] Draft~~ IS-GPS-800 Navstar GPS Space Segment/User Segment L1C Interfaces~~, 19 April 2006.~~</ref> the final phasing is still open. To finalize some details on the technical characteristics of the GLONASS L1 signals are presented next:		It is important to note that the GPS L1C pilot and data signals are shown in quadrature in the figure although according to [GPS ICD-800, 2024]<ref>[https://archive.gps.gov/technical/icwg/IRN-IS-800J-003.pdf IS-GPS-800 Navstar GPS Space Segment/User Segment L1C Interfaces]</ref> the final phasing is still open. To finalize some details on the technical characteristics of the GLONASS L1 signals are presented next:

	::::[[File:GLONASS_Sig_Plan_Table_1.png\|none\|thumb\|580px\|'''''Table 1:''''' GLONASS L1 signal technical characteristics.]]		::::[[File:GLONASS_Sig_Plan_Table_1.png\|none\|thumb\|580px\|'''''Table 1:''''' GLONASS L1 signal technical characteristics.]]
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	CDMA Open Service Navigation Signal in L1 frequency band is called L1OC. It is transmitted on carrier frequency		CDMA Open Service Navigation Signal in L1 frequency band is called L1OC. It is transmitted on carrier frequency
	f<sub>L1</sub> = 1565 f<sub>b</sub> = 313 x 5.115 MHz = 1600.995 MHz		f<sub>L1</sub> = 1565 f<sub>b</sub> = 313 x 5.115 MHz = 1600.995 MHz
	and consists of two components of the same power: L1OCd (data component) and L1OCp (pilot component). These components are obtained by chip by chip time-division multiplexing (TDM) of two pseudorandom noise sequences (PRNs). L1OC signal is in phase quadrature with L1SC signal, which is delayed by 90º.<ref name=L1>[~~http~~://~~russianspacesystems~~.ru/~~wp-content/uploads~~/~~2016~~/08/~~ICD-GLONASS-CDMA-L1.-Edition-1.0-2016~~.~~pdf~~ ICD GLONASS CDMA L1, ~~2016~~]</ref>		and consists of two components of the same power: L1OCd (data component) and L1OCp (pilot component). These components are obtained by chip by chip time-division multiplexing (TDM) of two pseudorandom noise sequences (PRNs). L1OC signal is in phase quadrature with L1SC signal, which is delayed by 90º.<ref name=L1>[https://glonass-iac.ru/upload/docs/stehos/stehos_en_app_D.PDF ICD GLONASS CDMA L1, 2023]</ref>

	=== L1OCd ===		=== L1OCd ===
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	f<sub>L2</sub> = 1220 f<sub>b</sub> = 244 x 5.115 MHz = 1248.06 MHz		f<sub>L2</sub> = 1220 f<sub>b</sub> = 244 x 5.115 MHz = 1248.06 MHz
	and is multiplexed with L2 CSI signal chip by chip time-division multiplexing of their pseudorandom noise sequences.		and is multiplexed with L2 CSI signal chip by chip time-division multiplexing of their pseudorandom noise sequences.
	L2q signal is in phase quadrature with L2SC signal, which is delayed by 90º <ref name= L2>[~~http~~://~~russianspacesystems~~.ru/~~wp-content/uploads~~/~~2016~~/08/~~ICD-GLONASS-CDMA-L2.-Edition-1.0-2016~~.~~pdf~~ ICD GLONASS CDMA L2, ~~2016~~]</ref>.		L2q signal is in phase quadrature with L2SC signal, which is delayed by 90º <ref name=L2>[https://glonass-iac.ru/upload/docs/stehos/stehos_en_app_D.PDF ICD GLONASS CDMA L2, 2023]</ref>.

	=== L2OCp ===		=== L2OCp ===
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	f<sub>L3</sub> = 1175 f<sub>b</sub> = 235 x 5.115 MHz = 1202.025MHz		f<sub>L3</sub> = 1175 f<sub>b</sub> = 235 x 5.115 MHz = 1202.025MHz

	and consists of two BPSK(10= components of the same power: L3OCd (data component) and L3OCp (pilot component). These components are in phase quadrature with each other and L3OCd is delayed 90º <ref name=L3>[~~http~~://~~russianspacesystems~~.ru/~~wp-content/uploads~~/~~2016~~/08/~~ICD-GLONASS-CDMA-L3.-Edition-1.0-2016~~.~~pdf~~ ICD GLONASS CDMA L3, ~~2016~~]</ref>.		and consists of two BPSK(10= components of the same power: L3OCd (data component) and L3OCp (pilot component). These components are in phase quadrature with each other and L3OCd is delayed 90º <ref name=L3>[https://glonass-iac.ru/upload/docs/stehos/stehos_en_app_D.PDF ICD GLONASS CDMA L3, 2023]</ref>.

	=== L3OCd ===		=== L3OCd ===

Gema.Cueto: /* L1OCd */

2019-10-30T13:35:29Z

L1OCd

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	=== L1OCd ===		=== L1OCd ===

	Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCd</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, overlay code (OC1) symbol stream clocked at 500 sps, and convolution encoder (CE) symbol stream clocked at 250 sps.		Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCd</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, overlay code (OC1) symbol stream clocked at 500 sps, and convolution encoder (CE) symbol stream clocked at 250 sps <ref name=L1></ref>.

	Navigation message of L1OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.		Navigation message of L1OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.

Gema.Cueto: /* L1OCp */

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L1OCp

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	=== L1OCp ===		=== L1OCp ===

	Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCp</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, and meander sequence (MS) clocked at: 2 f<sub>T1</sub> = 2.046 MHz.		Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCp</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, and meander sequence (MS) clocked at: 2 f<sub>T1</sub> = 2.046 MHz<ref name=L1></ref>.

	The MS is a 0101 periodic sequence, synchronized with PRNL1OCp chips and transmitted with most significant bits ahead. MS is intended to form BOC (1, 1) spectrum for L1OCp component<ref name=L1></ref>.		The MS is a 0101 periodic sequence, synchronized with PRNL1OCp chips and transmitted with most significant bits ahead. MS is intended to form BOC (1, 1) spectrum for L1OCp component<ref name=L1></ref>.

Gema.Cueto: /* L3OCp */

2019-10-30T13:32:34Z

L3OCp

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	=== L3OCp ===		=== L3OCp ===

	Modulation sequence of symbols of L3OCp signal is the modulo-2 sum of PRN<sub>L3OCp</sub> chip stream clocked at f<sub>T1</sub> = 10.23MHz and Newman-Huffman code (NH) symbol stream clocked at 1000 sps. Sequence S<sub>L3OCp</sub> is used to phase-shift key Q-component of carrier frequency in L3 by 180º.		Modulation sequence of symbols of L3OCp signal is the modulo-2 sum of PRN<sub>L3OCp</sub> chip stream clocked at f<sub>T1</sub> = 10.23MHz and Newman-Huffman code (NH) symbol stream clocked at 1000 sps. Sequence S<sub>L3OCp</sub> is used to phase-shift key Q-component of carrier frequency in L3 by 180º <ref name=L3></ref>.

	==References==		==References==

Gema.Cueto at 13:29, 30 October 2019

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	\end{array}		\end{array}
	\qquad \mbox{(1)} </math>		\qquad \mbox{(1)} </math>


	::where:		::where:
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	::<math>f_{0_{L3}}</math> = 1201 MHz for the GLONASS L3 band, and		::<math>f_{0_{L3}}</math> = 1201 MHz for the GLONASS L3 band, and
	::<math>\Delta f_{L3}</math> = 437.5 kHz frequency separation between GLONASS carriers in the L3 band.		::<math>\Delta f_{L3}</math> = 437.5 kHz frequency separation between GLONASS carriers in the L3 band.


	The new GLONASS-K satellites transmit additional signals. GLONASS-K1 transmit a CDMA signal on a new L3 frequency (1202.025 MHz), and GLONASS-K2, in addition, will feature CDMA signals on the L1 and L2 frequencies.		The new GLONASS-K satellites transmit additional signals. GLONASS-K1 transmit a CDMA signal on a new L3 frequency (1202.025 MHz), and GLONASS-K2, in addition, will feature CDMA signals on the L1 and L2 frequencies.

	Like GPS and the other GNSSs, the GLONASS signals also contain navigation messages providing satellite orbit, clock and other information. Separate 50-bits-per-second navigation messages are modulo-2 added to the ST- and VT-codes. The ST-code message includes satellite clock epoch and rate offsets from GLONASS System Time; the satellite ephemeris given in terms of the satellite position, velocity and acceleration vectors at a reference epoch; and additional information such as synchronization bits, data age, satellite health, offset of GLONASS System Time from Coordinated Universal Time (UTC) as maintained by the National Metrology Institute of the Russian Federation UTC(SU) as part of the State Time and Frequency Service, and almanacs (approximate ephemerides) of all other GLONASS satellites<ref name=gpsworld></ref>.		Like GPS and the other GNSSs, the GLONASS signals also contain navigation messages providing satellite orbit, clock and other information. Separate 50-bits-per-second navigation messages are modulo-2 added to the ST- and VT-codes. The ST-code message includes satellite clock epoch and rate offsets from GLONASS System Time; the satellite ephemeris given in terms of the satellite position, velocity and acceleration vectors at a reference epoch; and additional information such as synchronization bits, data age, satellite health, offset of GLONASS System Time from Coordinated Universal Time (UTC) as maintained by the National Metrology Institute of the Russian Federation UTC(SU) as part of the State Time and Frequency Service, and almanacs (approximate ephemerides) of all other GLONASS satellites<ref name=gpsworld></ref>.


	To have a clearer insight into how the spectra of the GLONASS signals look like, we study next all the bands in detail.		To have a clearer insight into how the spectra of the GLONASS signals look like, we study next all the bands in detail.


	== GLONASS L1 Band ==		== GLONASS L1 Band ==

Gema.Cueto: /* L1OCp */

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L1OCp

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	Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCp</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, and meander sequence (MS) clocked at: 2 f<sub>T1</sub> = 2.046 MHz.		Modulation sequence of symbols of L1OCd signal is the module-2 sum of PRN<sub>L1OCp</sub> chip stream clocked at f<sub>T1</sub>/2 = 0.5115 MHz, and meander sequence (MS) clocked at: 2 f<sub>T1</sub> = 2.046 MHz.

	The MS is a 0101 periodic sequence, synchronized with PRNL1OCp chips and transmitted with most significant bits ahead. MS is intended to form BOC (1, 1) spectrum for L1OCp component.		The MS is a 0101 periodic sequence, synchronized with PRNL1OCp chips and transmitted with most significant bits ahead. MS is intended to form BOC (1, 1) spectrum for L1OCp component<ref name=L1></ref>.

	== GLONASS L2 Band ==		== GLONASS L2 Band ==

Gema.Cueto: /* L3OCd */

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L3OCd

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	=== L3OCd ===		=== L3OCd ===

	Modulation sequence of symbols of L3OCd signal is the module-2 sum of the PRN<sub>L3OCd</sub> chip stream clocked at f<sub>T1</sub> = 10.23MHz, Barker code (BC) symbol stream clocked at 1000 sps, and convolution encoder (CE) symbol stream clocked at 200 sps. Sequence S<sub>L3OCd</sub> is used to phase-shift key I-component of carrier frequency in L3 by 180º <ref name= L3>.		Modulation sequence of symbols of L3OCd signal is the module-2 sum of the PRN<sub>L3OCd</sub> chip stream clocked at f<sub>T1</sub> = 10.23MHz, Barker code (BC) symbol stream clocked at 1000 sps, and convolution encoder (CE) symbol stream clocked at 200 sps. Sequence S<sub>L3OCd</sub> is used to phase-shift key I-component of carrier frequency in L3 by 180º <ref name= L3></ref>.

	Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.		Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.

	Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name=L3> </ref>.		Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name=L3></ref>.

	=== L3OCp ===		=== L3OCp ===

Gema.Cueto: /* GLONASS L1 Band */

2019-10-30T13:26:42Z

GLONASS L1 Band

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	CDMA Open Service Navigation Signal in L1 frequency band is called L1OC. It is transmitted on carrier frequency		CDMA Open Service Navigation Signal in L1 frequency band is called L1OC. It is transmitted on carrier frequency
	f<sub>L1</sub> = 1565 f<sub>b</sub> = 313 x 5.115 MHz = 1600.995 MHz		f<sub>L1</sub> = 1565 f<sub>b</sub> = 313 x 5.115 MHz = 1600.995 MHz
	and consists of two components of the same power: L1OCd (data component) and L1OCp (pilot component). These components are obtained by chip by chip time-division multiplexing (TDM) of two pseudorandom noise sequences (PRNs). L1OC signal is in phase quadrature with L1SC signal, which is delayed by 90º.<ref>[http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD-GLONASS-CDMA-L1.-Edition-1.0-2016.pdf ICD GLONASS CDMA L1, 2016]</ref>		and consists of two components of the same power: L1OCd (data component) and L1OCp (pilot component). These components are obtained by chip by chip time-division multiplexing (TDM) of two pseudorandom noise sequences (PRNs). L1OC signal is in phase quadrature with L1SC signal, which is delayed by 90º.<ref name=L1>[http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD-GLONASS-CDMA-L1.-Edition-1.0-2016.pdf ICD GLONASS CDMA L1, 2016]</ref>

	=== L1OCd ===		=== L1OCd ===
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	Navigation message of L1OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.		Navigation message of L1OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.

	Navigation message of L1OCd signal is transmitted at 125 bps. It consists of 250-bit strings of 2 second duration, as well as of 125 and 274 bit anomalous strings of 1 and 3 second duration, respectively.		Navigation message of L1OCd signal is transmitted at 125 bps. It consists of 250-bit strings of 2 second duration, as well as of 125 and 274 bit anomalous strings of 1 and 3 second duration, respectively<ref name=L1></ref>.

	=== L1OCp ===		=== L1OCp ===

Gema.Cueto: /* L3OCd */

2019-10-30T13:25:35Z

L3OCd

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	Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.		Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.

	Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name=L3></ref>.		Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name=L3> </ref>.

	=== L3OCp ===		=== L3OCp ===

Gema.Cueto: /* GLONASS L3 Band */

2019-10-30T13:25:18Z

GLONASS L3 Band

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	f<sub>L3</sub> = 1175 f<sub>b</sub> = 235 x 5.115 MHz = 1202.025MHz		f<sub>L3</sub> = 1175 f<sub>b</sub> = 235 x 5.115 MHz = 1202.025MHz

	and consists of two BPSK(10= components of the same power: L3OCd (data component) and L3OCp (pilot component). These components are in phase quadrature with each other and L3OCd is delayed 90º <ref name= L3>[http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD-GLONASS-CDMA-L3.-Edition-1.0-2016.pdf ICD GLONASS CDMA L3, 2016]</ref>.		and consists of two BPSK(10= components of the same power: L3OCd (data component) and L3OCp (pilot component). These components are in phase quadrature with each other and L3OCd is delayed 90º <ref name=L3>[http://russianspacesystems.ru/wp-content/uploads/2016/08/ICD-GLONASS-CDMA-L3.-Edition-1.0-2016.pdf ICD GLONASS CDMA L3, 2016]</ref>.

	=== L3OCd ===		=== L3OCd ===
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	Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.		Navigation message of L3OCd signal is transmitted as a continuous sequence of strings of non-fixed and non-predetermined structure.

	Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name= L3></ref>.		Navigation message of L3OCd signal is transmitted at 100 bps. Navigation message consists of 300-bit strings of 3-second duration, as well as of 200 and 400-bit anomalous strings of 2 and 4 second duration respectively <ref name=L3></ref>.

	=== L3OCp ===		=== L3OCp ===